See images for drill sizes included. Comes in two ten-piece professional cases to keep your tools secure and organized. 1/8" shanks fit most rotary tools. Factory Resharpened, same performance as new for less. This 20 piece solid carbide drill set is perfect for engine main jets and pilot jets of many carburetors, including motorcycle and R/C engines. Carbide drills are brittle and require precise plunge control, use in a rotary type tool held in a drill press stand attachment or by hand carefully with a pin vise. Do not attempt to use in a hand-held electric drill, they will break.